A portable electronic device means an electronic device designed for portable use, such as mobile phones, camcorders, PDAs, PMPs, smart pads, tablet PCs, notebooks, and is generally supplied with a power through a battery. Recently, due to the development of smart technologies, the portable electronic device began to perform multiple functions, and due to the introduction of touch screen technologies, the size of a liquid crystal screen has gradually become larger, such that a power supply for the portable electronic device has emerged as an important issue. Therefore, a high-capacity battery has been developed, but there is a limit to increase a capacity of the battery in terms of maintaining portability. Thereby, electronic device companies typically provide a spare battery which is configured and employed for allowing a user to carry and replace the discharged battery with the spare battery, as necessary. In a case of employing a system of replacing the battery, it is not possible to use the portable electronic device during times of replacing the battery, and there is an inconvenience that a time is required for booting up the electronic device upon turning on and off the same. In particular, in the case of a mobile phone, the user may not receive an important call while replacing the battery, and a variety of programs should be restarted, such that it takes a very long time to boot up the mobile phone.
Thereby, research into how to maintain the power even when replacing the battery has been actively proceeded in recent years. Korean Utility Model Registration Application No. 20-2003-0032216 discloses a structure configured in such a manner that slide guiding grooves are formed in a battery mounting part of a mobile phone, a battery slides along the guiding grooves so as to be attached or detached to or from the battery mounting part, and during sliding the battery along the guiding grooves, power supply terminals of the battery that has reached a potential of end-stage of use may be maintained in a state of contacting power supply terminals of the mobile phone when inserting a new battery into the guiding grooves and sliding the same, until power supply terminals of the new battery come into contact with the power supply terminals of the mobile phone. However, this method has problems that, since another battery should be inserted into the guiding groves with only a portion of the previously mounted battery being separated from the battery mounting part, the battery replacement method is not easy, and applying the method to a currently largely used battery contact structure is difficult. Further, a variety of methods for supplying an auxiliary power to the mobile phone has been studied, but a specific method for allowing the mobile phone to have a power maintenance function while using the conventional battery contact system has not been developed up to now.